Electric circuit interrupter



Oct. 28,1941. G. F. LlNcKs ELECTRIC CIRCUIT INTERRUPTER Filed Sept. 8, 1939 5 Sheets-Sheet l IAT15ulatio-n tion Infanta Inventor: George F? Lwncks,

y l Attorney.

Oct. 28, 1941. G. F. LlNcKs ELEC'QIRIG CIRCUIT INTERRUPTER Filed Sept. 8, 1959 3 Sheets-Sheet 2 /56 Inventor: George F Lncks,

His Attorngy- Oct. 28, 1941. G. F. LlNcKs v 2,260,751

ELECTRIC CIRCUIT INTERRUPTER Filed sept. 8, 1939 3 sheets-sheet 3 Hls Aitor-hay Patented Get. 2S, 194i ELECTRIC CIRCUIT INTERRUPTER George F. Lincks, Plttsield, Mass., assigner to General Electric Co New York mpany, la. corporation o! Application September 8, 1939, SerialANo. 293,966

(Cl. Zim-114) 12 Claims.

The present invention relates to electric circuit interrupters, and more particularly to circuit interrupters such as, for example, dropout fuse cutouts, which incorporate 'a movably mounted switching assembly including an insulating holder 'for supporting an automatically operable circuit interrupting means, together with mechanism capable of functioning autcmatically upon operation of the circuit interrupting means to effect movement of an element or elements of the switching assembly from an operative position to a dropped-out position or other position giving indication of circuit interruption.

The invention has for one of its objects the provision, in a circuit interruptor -such as reerred to above, of improved construction and arrangement of supporting and latching mechanism wherebyrelease of the switching assembly from an operative position upon operation of the circuit interrupting means is effected without the necessity for movement of the insulating holder oi the switching assembly.

Another object is the provision, in a drop-out circuit interruptor of the enclosed type, of improved mechanism whereby release of the" switching assembly from operative position upon operation of the circuit interrupting means is Y effected in response to movement oi a, cover or door of the casing Aof the circuit interruptor, and independently 'ci movement o the insulating holder which forms part of the switching assembly and serres to support the circuit interrupting means.

The invention has also, for one of its objects,

the provision of improved mechanism for carrying out features of the invention disclosed and more broadly claimed in my earlier application assignee` as the present invention.

Serial No. 248,085, iiled December 28, 1938 now Patent No. 2,197,646, and assigned to the same' Other objects and the details of that which I believe to be noveland my present invention will become apparent fromV the following description and the claims appended thereto, taken in conjunction with the accompanying drawing whereoperative positions; Fig. 2 is a side elevation,`

partially in section, showing an intermediate stage in the operation of the cutout of Fig. 1;

Fig. 3 is a partial sectional elevation of the cutout of Fig. 1, showing certain of the parts in dropped-out position; Fig. i is a sectional plan viewtaken along the line i of Fig. 1; Fig. 5 is a side elevation, partially in section. of a fuse cutoutv incorporating a second exemplary embodiment oi the invention, with the parts thereof in normal operative positions; Figs. 6, 7, and 8 are side elevations. partially in section, showing the positions of certain of the parts of the cutout of Fig. 5 in three successive stages of operation following use operation; Fig. 9 is a sectional plan view taken along the line 9-9 ci Fig. 5; Fig. 10 is 'an enlargement of the showing of the bottom portion oi Fig. 5; Fig. l1 is a view looking up at the bottom of the cutout of 5, and Fig. 12 is an exploded perspective (which has an integrally formed electric creepage and gas barrier 2l on the inner rear wall thereof. On theback of the casing is a mounting 'oar 22 for attachment to an electric line pole and cross-arm structure or other suitable support. Terminal contacts 23 and 2t are attached on the inner rear wall oi' the casing respectively above and below barrier 2l andl are provided with suitable sockets and clamping screws, vindicated at 25, for attachment of line conductors or leads thereto. Upper contact 2t has a iorwardly extending resilient contact iinger 28, backed by a spring strip 21, which is arranged to engage a terminal cap on thevtop oi a fuse holder.l The forward free ends of finger 25 and strip 2l are 'curved upwardly as indicated at ,28 to facilitate engagement of a fuse h'older'cap therewith. .A U-shaped latchng element 29 also is secured to contact 23 in such manner that the resilient arms 30 of the element extend forwardly in substantially parallel and horizontally spaced relationship. The outer ends oi arms 30 have inwardly facing detent seats Si and outwardly flared guide portions 32, 'as will be seen best in Fig. 4.

an' elongated tubular holder 35, a hinge element 34, and a cover or door 3c for the open iront oi the casing The holder 33, whichds constructed of brous or 'other suitable insulating material. is open at the lower enel for expulsion of gases therefrom and is closed at the upper end by a removable contact cap 3i. This holder serves to accommodate in a well known manner a circuit interrupting element in the form of a fuse link, the upper end of which link is electrically connected with cap 36, and the lower A element 34 has a hook 43 engageable with a` hinge bracket 84 on the casing for'hingedly supporting the switching assembly. A, contact iinger 145 is plvotally mounted on a pin 48 extending between arms 4 offthe hinge element. This contact iinger is biased by means of a coil spring 13'! for rotation in a counterclockwise direction, as viewed in (the drawings, to effect pressure eni gagenient of the contact finger with lower stationary contact 24. Hinge element 34 also has suitable fuse link clamping means, indicated at Cover 35 is constructed of insulation, and has on'the outer side thereof an eyelet handle I0. n the inner side of the cover is a projection having a tapered slot 52 for loosely receiving and supporting the upper end of holder 33. A spring finger 53, moxmted on the inner side of the door, presses the holder nrmly against the left-hand side of the slot l2, as viewed in the drawings. A collar I4 is nxedly secured on the lower end of the holder, and this collar has a bearing screw 55 which relatively, loosely engages' a slot 58 in the lower end of hinge element I4 for pivotaly supporting the holder. Normally the lower end of the cover, the lower end of the holder, and the hinge element are releasably sethe elements o! the switching assembly. Such relative movement between the cover and holder is made possible by the size and tapered shape of slot 52 in cover projection 5|, and by the relatively loose pivotal connection of the lower end of the holder with the hinge element at a point spaced from the pivotal connection between the hinge element and cover' projections 4|.' If desired, a stirrup (not shown) may be employed for restraining the lower end of the cover in a partially open indicating position, and without unlatching of the upper end of the cover, in the manner shown in my application previously referred to herein, and also in U. S. Patent 2,081,813, to B. R. Hermann, issued May 25, 1937, which patent also is assigned to the same vassignee as the present invention. However, ii such stirrup is not employed, as in the illustrated embodiment, the cover continues to move outwardly and downwardly in a manner to effect disengagement or` prongs 8| from detent seats 3|, as shown in Fig. 2. As soon as the upper end of the cover is released, the switching assem- `bly swings outwardly and downwardly about hinge bracket 44 to the position shown in Fig. 3, wherein the fuse holder is completely isolated from stationary contacts I; and 24. It is to be noted that the unlatching of the switching assembly is eiiected by movement o! the cover and without the necessity for movement of the holder since the holder itself is not engaged by any latching means. v

In the embodiment of Figs. 5-12,` the insulating casing 2l has stationary terminal contacts Il and I4 mounted onthe inner rear wall thereof respectively above and below barrier 2|. Each o! these contacts is provided with suitable socket and clamping means indicated at il, for attachment of .line conductors or leads which may be brought into the casing through openings such as indicated at I2. v Upper contact ll includes a cured in substantially rigid relationship by f means of fuse link extension 31 which is looped through a hook 51, on the lower inner face of g the cover, and is secured to the hinge element by clamping means 48. Thus there is provided a relatively rigid switching assembly which, by

l means of handle 50, may be swung about hinge bracket 44 into and out of an operative 'posi.

tion relative to stationary contacts 2l and 2,4.

For releasably latching the upper end of the switching assembly in operative position, a latch element 6 0 is secured on the inner side of the cover adjacent the upper end thereof. AThis' latch element has horizontally spaced prongs Il which upon rotation of cover 35 to closed podtion, engage respectively with guide portions 32 of resilient latching arms Il and pass into latching engagement with detent seats 3|. With the cover latched as shown in Figs. 1 and 4, contact iinger 28 bears on the top of contact cap 38 to eiiect electriccon'nection with the upper, vend of the fuse link in holder 33, while spring linger El resists loose movement of the holder.

Thelower endwof the fuse link is electrically A connected with lower stationary' contact 24 through hinge element 34 and contact finger 45.

contact plate and abacking plate 61 secured to a contact support il by means of screws il.

`'13 extending forwardly respectively on opposite sides of contact finger 1l and provided adjacent vtheir outervends with'downwardly facing datent seats 14 and upwardly curved guide portions 1I. Backing plate I1 has afforwardly' extending spring linger 18 which backs up contact nnger 1l.

Onthe innerrearwallofcasing 2l, and adiacent the bottom thereof, are mountedv in horizontally spaced relation two hinge brackets 1'I and 1l providedrespectively with hinge pins 1I. These'brackets are pivotally to support a switching ly which includes the fuse holder 38, a cover Il for the open front o'f lthecasing,andhingemechanislnnowtobedeexerted by contact anger 4s and the weight ons in rigs s-sand 1o. 'me' other end of um si from the bottom wall of section ||1.

is iixedly attached to a collar 83 which is ilxedly ,1 vided respectively in plates lll and nl of toggle clamped on the lower .end of holder 33 by means e of a bolt or other suitable means, indicated at 34. Attachment o! arm 8| to collar 83 is effected by means of a screw and a drive stud 36.

lever Il and in alinement with each other. The

^ slot |23 in plate ||3 accommodates the spacing Screw 35 passes through an opening 81 in arm 3| and into screw-threaded engagement with a hollow boss 88 supported on a lug 89 depending from collar 93. Drive stud I6 passes through opening 90 in arm 8| and through a spacing sleeve 9| into a socket 92 in a lug 93 depending from collar 83.

Cover 80 is constructed of insulation and is supported by toggle mechanism which in general is ofthe improved form disclosed in U. S. Patent #2,081,814 to B; R. Hermann, issued. May 25,

1937, and assigned to the same assignee as the presentinvention. This toggle mechanism includes a toggle lever, generally designated 95 on the drawings, and a U-shaped bracket 96 which is iixedly attached to the inner face of cover 80 by means of screws, rivets, or the like, indicated at 91. The plates 98 and 99, forming the legs of bracket 96, extend inwardly from the cover in horizontally spaced relationship so as loosely to accommodate holder 33 therebetween. Formed respectively in plates 98 and 99 are two alined openings in which are mounted screws |0| which serve rotatably to support rollers |02 located respectively on the outer sides of plates 98 and 99. A second pair of rollers |03, located respectively on the outer sides of plates 98 and 99, are rotatably supported on screws |04 mounted in alined openings |05 respectively in plates 98 and 99.

Toggle lever 95 comprises in the main two sleeve 9| on drive stud 36, while the slot |23 in plate accommodates a cylindrical boss |24 which is supported on ay lug depending yfrom collar I3 in horizontal alinement with the` previously referred to lug 93'. A screw |26 serves to prevent disengagement of boss |24 from the slot |23 in plate `'I'hus cover 30 and its supporting toggle lever 95 are afforded support on hinge bracket 11 as well as on hinge bracket 18, while fuse holder 33 with its supporting arm 8| are ailorded support on hinge bracket 18 as well as on hinge bracket". The slidable connection, ailorded by slots |23 as described above, between toggle lever 95 on the one hand and collar 63 and arm- 8| on the other hand, prevents undesirable loose movement of the toggle lever, bracket 96, and fuse holder 33 relative to each other in horizontal planes, while providing for movement of the cover and toggle lever relative to the fuse holder and its supporting arm 9| during the unplates I0 and which are rigidly braced in' lparallel horizontally spaced relationship by means of a stirrup ||2 and a rod I|3, and which plates are arranged to receive bracket 96 therebetween. The upper parts of plates ||0 and are provided respectively with vertically extending alined slotsA ||4 for receiving rollers |02 on bracket 96. Two alined slots ||5 are provided respectively in plates ||0 and approximately at the middle of these plates, for receiving the rollers |03 on bracket 96. Each of the slots I5 is formed to provided two guide sections, the nrst of which, designated H6, has a lower edge which slants upwardly and outwardly as viewed when toggle lever 95 is in its vertical position shown in Figs. 5 and 10, and the second of which sections, designated ||1, extends slightly downwardly at an angle to the section ||6. A relatively abrupt peak 8 divides the bottom wall of section 6 'I'he engagement of rollers |02 and |03 with slots ||4 andx ||5 respectively provides a pivotal connection between lever 95 and the bracket 96 on cover 80. v

Lever 95 is designed hingedly to support cover 90 independently of and movably relative to holder 33. To this end, plate of the lever has a hook-shaped portion |20 engageable with the hinge pin 19 of hinge bracket 18, which latter hinge bracket is on the far side of casing 20, as viewed in Figs. 5-8 and 10.' Plate I0 of the hinge lever does not have a corresponding hook portion for engagement with hinge bracket 11, but is cut away, as indicated at |2|, so as to accommodate the inwardly oilset portion |22 of hinge arm 8|, as will be best seen in Fig. 10. In order to improve the stability of the supporting mechanism and prevent undesired movement between the parts thereof, two curved slots |23 are prolatching operation more fully described hereinafter.

Toggle lever 95* is provided with a contact ringer for making contact with lower stationary contact 64. This contact finger comprises a supporting plate |30, a contact nose piece |3I, and a iiexible connection strip |32 of good conductivity. Plate |30 has trunnions |33 which engage openings |34 respectively in plates ||0 and for pivotally supporting the contact finger. Nose piece |3| and the upper end of exible strip |32 are secured to the upper end of plate |30 by rivets or other suitable means, as indicated at |35. The lower end of strip |32 extends below plate |30 and is attached to the bottom of 4stirrup ||2 so as to provide a fuse link terminal, which terminal includes a wing nut |36 for clamping the end ofl fuse link extension 31 thereto. A tension spring |31, connected at'the upper end to plate |30, as indicated at |38, and connected at the lower end to crossbar ||3, is provided for biasing the nose piece |3| of the contact ringer into engagement with stationary contact 64.

The' upper end of fuse holder 33 extends througha tapered slot |40 in a projection '|4I formed integrallywith, and on the inner side of, cover 30, and a spring finger |42 on the cover tends to bias the holder toward the left, as viewed in the drawings, into engagement with the tapered left-hand side of slot |40. Normally, the lower end of cover and its supporting toggle lever are secured in substantially rigid relation to the lower end of holder 33, and in the relative positions shown on Figs. 5 and 10, by means of fuse link extension 31 which is passed through a hook |43 on the lower inner face of the cover and clamped to stirrup ||2 of the toggle lever by wing-nut |36. With the cover, toggle lever, and holder so secured, hook 82 of holder supporting hinge arm 3| and hook |20 of toggle lever plate may be engaged with hinge brackets 11 and 18 respectively, whereupon the switching assembly may be swung, by means of door handle |44, and about the hinge-brackets, into and out of the operative position shown in Fig. 5. 0n the upper inner face of the cover is mounted a latch element |45 having two prongs |46 which extend horizontally in opposite directions and are engageable respectively with the detent seats 14 When the switching assembly is in operative position, spring nger |42 maintains fuse holder contact cap 36 in rm engagement with the shoulder at the rear of contact seat 1| in stationary contact iinger 10, while the seat portion 5 1| of the stationary contact finger presses on the top of cap 36 to effect good electric connection with the upper end of the fuse link in holder 33. Connection of the lower end of the fuse link is effected through flexible connector strip |32 and 10 nose piece |3|, which last is held in rm engagement with lower stationary contact 64 by means of spring |31. The pressure of the contact finger, including nose piece |3|, against contact 64, tends to eiect rotation of the switching assembly to open positiony but such action is prevented by the previously described latch mechanism at the upper end of the switching assembly.

Upon rupture of the fuse link in holder 33, due

to overload or short-circuit, toggle lever 95 is'20 released by the fuse link cable extension 31, and swings outwardly due to the action of spring |31 and contact finger |30, with resultant outward swinging of the lower end of cover 80. Were it not for the form of slots ||5 in the toggle lever 25 and the engagement of rollers |03 therewith,the lower end of the cover would pivot about the roller |02 in slots ||4 of the toggle lever and the cover would at the .same time move bodily downward under the combined action of gravity and 30 the force of the outwardly and downwardly swinging toggle arm. However, the form or sections |I6 of slots II5 acts to compensate for the tendency of the toggle lever to move the cover bodily downwardly and actually prevents such35 bodily downward movement during the initial stages of movement of the cover, so that latch element does not become disengaged from latching fingers 13. In effect, the slot sections I I6 serve as guideways to limit initial movement 40 of the cover substantially to a counterclockwise pivoting of the. lower end of the cover about its upper end. During this initial pivoting of the cover, toggle lever 95 swings relative to holder supporting arm 8|, as peviously explainedand. 45

the fuse holder itself does not move since spring iinger |42 maintains the upper end of the holder in engagement with contact nger 10 as long as latch prongs |46 on the cover remain in engagement with detent seats 14. swinging of the lower end of the' cover relative to the lower end of the fuse holder effects a relatively rapid retraction of fuse link extension 31 from the fuse holder so as to draw out the arc within the fuse holder and thereby aidin circuit.

the releasing action, rollers |03 ride upwardly in. 65

the left-hand sections ||6 of slots ||5, While upward movement of rollers |02 in slots ||4 provides for the necessary lost motion. If it is desired to have only an indication of fuse operation, without complete drop-out of the switchf ing assembly, stops |50 may be placed in openings |5I in plates |I0 and III of toggle lever 95, so as to prevent roller |03 from riding over humps I I8 in slots IIS, all as fully described in the previously referred to Patent 2,081,814.01' B. R.75

The outward.I 50

As a result of this',` 60

Hermann. If this expedient is employed, the releasing action will cease when rollers |03 engage stops I 50 and the parts of the switching assembly will remain in their positions shown in Fig. 6, wherein it will be seen that the upper end of cover remains latched, while the lower end of the cover extends outwardly in a partially open position to give the desired indication while still protecting the internal parts of the cutout from adverse weather conditions.

If stops |50or the like are not employed, rollers |03 continue to move outwardly in slots II5 until they pass over humps ||8 When rollers |03 enter slot sections II1, cover 00 no longer is held in its raised position and is free to move so as to effect release of latch prongs |46 from engagement with detent seats 14 of stationary latch fingers 13, as shown in Fig. 7. When the upper end of the cover becomes unlatched the upper end of the fuse holder no longer is restrained in operative position and the whole switching assembly swings in a clockwise direction about hinge brackets 11 and 18 to an approximately horizontal dropped-out position, partially shown in Fig. 8, wherein the switching assembly is stopped' by engagement of plates ||0 and III of the toggle lever with projections |52 on the hinge brackets.

In connection with the last described embodi ment, as with the ilrst embodiment, it is to be noted that unlatching of the switching assembly for movement to dropped-out position'is eiected by movement of the cover and without the necessity ior movement of the fuse holder since the holder itself is not engaged by any` latching means, but is held in operative position only by reason of the latching of the cover.

It will be evident to one skilled in the art that the present invention is not limited strictly to the details of the constructions herein described and illustrated, and that 'modifications of the supporting mechanism, latching mechanism, and other parts may-be made in carrying out the invention, hence it is intended that such modifications as do not depart from the true spirit of the invention shall come within the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

' 1. In a circuit interrupter including an insulating support having spaced contacts thereon; a switching assembly movably mounted on said support and comprising an insulating holder having automatically operable circuit interrupting means, an auxiliary member distinct from said holder, means movably supporting said holder and said member and providing for relative movement between said member and holder, said supporting means including 'a hinge element hinged on said support and pivotally Joined to said member, said hinge element and said member being releasably secured in substantially rigid relationsihp by means releasable in response to operation of said circuit interrupting means, said hinge element being movable relative to said holder and said member upon release of said securing means, an element on said member engageable with a cooperative element on said support releasably to latch said assembly with said holdery in an operative position, and means including said hinge element operative upon release of said securing means to effect movement of said member relative toA said holder and hinge element.

2. In a circuit interrupter including an insulating support having spaced contacts thereon; a switching assembly comprising an insulating holder having automatically operable circuit interrupting means, an auxiliary member distinct from and extending in substantially parallel juxtaposition with said holder, means pivotally supporting the assembly von said support and providing for relative movement between said member and holder, said supporting means including a toggle lever hinged on said support and pivotally joined with said member, said lever and said member being relea'sably secured in substantially rigid relationship by means releasable' in response to operation of said circuit interrupting means, means on said member engageable with cooperating means on said support releasably to latch said member in a predetermined position relative to said support, said member secured and latched as aforesaid being operative to maintain said holder in an operative position, and means including said toggle lever operative upon release of said securing means to effect movement or said member relative to said holder and in a manner to cause disengagement of said latching means, thereby to free said holder for movement of the holder to a dropped-out position.

3. In a circuit interrupter including an insuan insulating support, spaced contacts thereon,

, an insulating holder having automatically operlating support having spaced contacts thereon;

a switching assexnbhr comprising an elongated tubular insulating holder having a fuse link tially rigid relation to said lever, latch means on said member engageable with detent means -V on said support releasably to latch-said member in a predetermined position relative to the support, said member secured and latched as aforesaid being operative to restrain said holder in an operativeposition, and means including said lever operative upon rupture of said f use link to effect movement of said member relative to said holder and said support.

' 4. In a circuit interrupter, the combination of an insulating support, spaced contacts thereon, an insulating holder having automatically operable circuit interrupting means, an auxiliary member distinct from said holder, a hinge element hinged on said support and movably supporting said holder and said member, said hinge element being pivotally joined to said holder and to said' member respectively at two different points to provide vfor relative movement between said holder and said member, means releasably securing said member against movement relative to said hinge element and being releasable in response to operation of said circuit interrupting means, and means on said member cooperative with means on said support releasably to latch y 5. In a circuit interruptor, the combination oi able circuit interrupting means, an auxiliary memberv distinct from said holder, two distinct hinge elements hinged on said support and movably supporting said holder and said member, one of said hinge elements being pivotally joined to said member, the other of the hinge elements being fixedly joined to said holder, meansl releasably securing said one hinge element and said member in substantially rigid relationship and being releasable responsively to operation of said circuit interrupting means, and means on said member cooperative with-means on said support releasably to latch said member in a predetermined position relative to said support, said member secured and latched as aforesaid being operative to restrain said holder' in an operative position for connection of said circuit interrupting meansbetween said contacts.

6. In a circuit interrupter, the combination of a casing having spaced contacts therein; a switching assembly including a cover for the casing and an insulating holder having automatically operable circuit interrupting means, together with means movably supporting said cover and holder on said casing and providing ,for relative movement between the cover and holder, said supporting means including a hinge element hinged on the casing and pivotally joined with the cover, said hinge element and cover being releasably secured in substantially rigid relationship by means releasable in response to operation of said circuit interrupting means; means operative, dependently upon said hinge element and cover being secured as aforesaid, releasably to latch said assembly so as to maintain said holder in an operative position; and

means including said vhinge element operative upon release of said securing means to eiect movement of said cover relative to said casing and holder.

'7. In combination, a casing, spaced contacts therein, a cover for the casing, a fuse holder,.a

Yhinge element hinged on the casing and pivotally joined with said cover for movably supporting the cover, means for movably supporting said holder in said casing, said hinge element and holder supporting means providing for relative movement between said cover and holder, means provided for mechanically securing a fuse link carried by said holder in a manner releasably to hold `said cover in substantially rigid relationship to said hinge element and holder, means on the cover engageable with means on said casing for releasably latching the cover in a predetermined position relative to the casing, means including the cover operative when the-cover is secured and latched as aforesaid to restrain said holder in an operative position, and means including said hinge element operative to eiect movement of the cover relative to said holder and casing upon rupture of a fuse link carried by the holder.

8. In a circuit interruptor, the combination of a casing, spaced contacts therein, a cover for the casing, an insulating holder having automatically operable circuit interrupting means, means movlable supporting said cover and holder and proably securing the cover and hinge element in substantially rigid relationship and operative to release the cover upon operation of said circuit interrupting means, means on the cover engageable with means on said casing to latch the cover, the cover secured and latched as aforesaid being operative to restrain said holder in an operative position, and means including said hinge element, operative upon release of thecover by said securing means, for effecting movement of the cover in a manner to release said latching means and for effecting movement of said holder to aposition electrically isolated from at least one of said contacts. l

9. In a circuit interrupter, the combination of to operation of a fuse link carried by the holder,

' andmeans on the cover arranged for latching a casing having spaced contacts therein; a switching assembly including a cover for the casing and an insulating holder having automatically 'operable circuit interrupting means, together with means for movably supporting said cover and holder including a hinge element hingedly mounted on said casing, said hinge element being pivotally joined with said cover and holder respectively at two different points so as to provide for relative movement between the cover and holder, said hinge element and cover being releasably secured .in substantially rigid relationship by means releasable in response to operation of said circuit interrupting means; and means operative. Adependently upon said` hinge element and cover being secured as aforesaid, for releasably latching said assembly in an operative position wherein said circuit interrupting means is connected between said contacts. g. 10. In a unitary switching device for removable installation in an electric cutout or like casing,

the combination of a fuse holder having spaced,

terminals for cooperation with spaced terminals of an' electric cutout or like casing,a cover for an open side of such casing, a hinge element having means for hinged mounting on such casing to support said cover and holder, said hinge element being pivotally joined to the cover and to the holder respectively at two different points so as to provide for relative vmovement between the cover and holder, means provided for releasably securing the cover relative to said hinge element and arranged for release of the cover in response engagement with cooperative means on an electric cutout or like casing so as to restrain said holder in an operativeposition in such casing.

11. In a circuit interrupter, the combination of a casing having spaced contacts therein; a switching assembly including a cover for the casing and an insulating holder having automatically operable circuit interrupting means, together with two distinct hinge elements hinged on said casing for movably supporting said cover and holder and providing for relative movement between the cover and holder, one of said hinge elements being joined to the holder, the other of the hinge elements beingpivotally joined to the cover and being releasably secured in substantially rigid relation to the cover by means releasable in response to operation ofsaid circuit interrupting means; and means operative, dependently upon said other hinge element and cover being secured as aforesaid, for releasably latching said assembly so as to restrain said holder in a position for connection of said circuit interrupting means between said contacts.

12. In a unitary switching device for removable installation in an electric cutout or like cas.. ing, the combination of a fuse holder having spaced terminals for cooperation with spaced terminals of an electric cutout or like casing, a cover for an open side of such casing, two distinct hinge elements each having means for hinged mounting on an electric cutout or like casing, which said elements are movable relative to each other while one of the elements is pivotally connected to said cover and the other of the elements is ilxedly joined to said holder, means provided for releasably securing said cover relative to said one hinge element and said holder and arranged for release of the cover in response to operation of a fuse link carried by the holder, and means on the cover arranged for latching engagement with cooperative means on an electric cutout or like casing to restrain said holder in an operative position in such casing. s

GEORGE F. LINCKS. 

